Characterization and catalytic behavior of EDTA modified silica nanosprings (NS)-supported cobalt catalyst for Fischer-Tropsch CO-hydrogenation

Alumina Coated Silica Nanosprings (NS) Support Based Cobalt Catalysts for Liquid Hydrocarbon Fuel Production From Syngas

“…The two higher temperature peaks at 373 °C and 492 °C for the Co/NS-Al-A catalyst and 395 °C and 557 °C for the Co/NS-Al-B catalyst are due to the reduction of Co 3 O 4 to CoO and CoO to Co 0 , respectively. The results obtained herein are in general agreement with data previously reported [1,14]. These results demonstrate that the preparation method for the surface coating of the NS with Al 2 O 3 impacted their reduction temperatures.…”

“…Moreover, the spin-orbit coupling (Δ SOC ) between the Co 2p 3/2 and Co 2p 1/2 in Co/NS, Co/Al 2 O 3 , Co/NS-Al-A and Co/NS-Al-B catalysts were 15.3 and 15.2 eV, 15.3 eV and 15.0 eV, respectively. Therefore, the weak satellite peaks observed for all the catalysts indicate that at the oxidation state of the catalysts are Co 3 O 4 phase, and this is in accordance with the literature [14,22]. The peak in the Co/NS-Al-A and Co/NS-Al-B catalysts at 782.2eV and 782.3 eV is tentatively assigned to the component of CoAl 2 O 4 [22].…”

“…Similar findings were reported by Saraswat et al [18] and Lee et al [19]. A broad diffraction peak assigned to amorphous silica NS was present (2θ ~ 23°) in the diffractograms of catalysts containing NS (Figure 3) [14]. The size of the Co 3 O 4 particles was calculated using Equation (4) of the Co 3 O 4 diffraction peak (311) at 2θ = 36.9°.…”

“…An additional band at 457 cm −1 is assigned to Si–O–Si or O–Si–O bending vibrations. The two absorption bands at approximately 586 cm −1 and 664 cm −1 in all catalysts have been assigned to Co–O [14]. Moreover, all catalysts exhibit a broad band centered at 3443 cm −1 associated with O–H stretching, and a relatively weak band at 1633 cm −1 of hydrogen bonded surface silanol groups and physically adsorbed water [16,20,21].…”

“…The Co/NS-Al-B had the highest O/P of 3.40. This increase in olefin content is likely attributable to a reduced hydrogenation rate [14]. The data reported above clearly shows that the addition of Al 2 O 3 to the NS support, in both the Co/NS-Al-A and Co/NS-Al-B catalysts, has an impact on the product selectivity and distribution of C 6 –C 14 aromatics.…”